IDR Working Group L. Yong
Internet-Draft S. Hares
Intended status: Standards Track Q. Liang
Expires: December 2, 2016 J. You
Huawei
May 31, 2016
BGP Flow Specification Filter for MPLS Label
draft-ietf-idr-flowspec-mpls-match-00.txt
Abstract
This draft proposes BGP flow specification rules that are used to
filter MPLS labeled packets.
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
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This Internet-Draft will expire on December 2, 2016.
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. The Flow Specification Encoding for MPLS Match . . . . . . . 3
3. Deployment Example: DDoS Traffic . . . . . . . . . . . . . . 5
4. Security Considerations . . . . . . . . . . . . . . . . . . . 5
5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 6
6. References . . . . . . . . . . . . . . . . . . . . . . . . . 6
6.1. Normative References . . . . . . . . . . . . . . . . . . 6
6.2. Informative References . . . . . . . . . . . . . . . . . 7
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 7
1. Introduction
BGP Flow Specification (BGP-FS) [RFC5575] is an extension to that
allows for the dissemination of traffic flow specification rules via
BGP ([RFC4271]). BGP-FS policies have a match condition that may be
n-tuple match in a policy, and an action that modifies the packet and
forwards/drops the packet. Via BGP, new filter rules can be sent to
all BGP peers simultaneously without changing router configuration,
and the BGP peer can install these routes in the forwarding table.
The typical application of BGP-FS is to automate the distribution of
traffic filter lists to routers for DDOS mitigation.
[RFC5575] defines a new BGP Network Layer Reachability Information
(NLRI) format used to distribute traffic flow specification rules.
NLRI (AFI=1, SAFI=133) is for IPv4 unicast filtering. NLRI (AFI=1,
SAFI=134)is for BGP/MPLS VPN filtering. [I-D.ietf-idr-flow-spec-v6]
defines flow-spec extension for IPv6 data packets.
[I-D.ietf-idr-flowspec-l2vpn] extends the flow-spec rules for layer 2
Ethernet packets (AFI=25, SAFI=133, SAFI=134). All these flow
specifications match parts only reflect single layer IP (source/
destination IP prefix, protocol type, ports, etc.) and Ethernet
information with matches for source/destination MAC
MPLS technologies [RFC3031] have been widely deployed in WAN
networks. MPLS label stack [RFC3032] is the foundation for label
switched data plane. A label on a label stack may represent a label
switch path (LSP), application identification such as Pseudo Wire
(PW), a reserved label that triggers a specific data plane action, or
etc. The data plane label switching operations includes pop, push,
or swap label on the label stack.
For value added services, it is valuable for a MPLS network to have
BGP-FS policy filter that matches on the MPLS portion of a packet and
an action to modify the MPLS packet header and/or monitor the packets
that match the policy. This document specifies an MPLS match filter.
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[I-D.liang-idr-bgp-flowspec-label] specifies a BGP action to modify
the MPLS label.
[I-D.hares-idr-flowspec-combo] describes the following two options
for extending [RFC5575]:
o Option 1: Extend [RFC5575] with new filters, match filters and
actions. Extend the match default order by type and require that
all matches be combined with an "AND". Extend the actions and
define a default order and the resolution of conflicts.
o Option 2: Create a version 2 of BGP flow Specification which can
run in parallel to Option 1 which supports explicit ordering of
match filters and actions. Option 2 will also refine the BGP-FS
security to optionally include ROAs between ASes, and other
mechanisms ([I-D.ietf-idr-bgp-flowspec-oid])
2. The Flow Specification Encoding for MPLS Match
This document proposes new flow specifications rules that is encoded
in NLRI.
Type TBD1- MPLS Match1
Function: The match1 applies to MPLS Label field on the label
stack.
Encoding: <type(1 octet), length(1 octet), [operator,value]+>.
It contains a set of {operator, value} pairs that are used for
matching filter.
The operator byte is encoded as:
0 1 2 3 4 5 6 7
+---+---+---+---+---+---+---+---+
| e | a | i | pos | Resv |
+---+---+---+---+---+---+---+---+
where:
e - end of list bit: Set in the last {op, value} pair in the
list.
a - AND bit: If unset, the previous term is logically ORed
with the current one. If set, the operation is a logical
AND. It should be unset in the first operator byte of a
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sequence. The AND operator has higher priority than OR for
the purposes of evaluating logical expressions.
i - before bit: If unset, apply matching filter before MPLS
label data plane action; if set, apply matching filter after
MPLS label data plane action.
pos - the label position indication bits: where:
00:any position on the label stack - the presented label
value is used to match any label on the label stack.
When apply it, at least one label on the stack match the
value
01:top label indication- the presented label value MUST be
used to match the top label on the label stack.
10: bottom label indication- If it is set, the presented
label value MUST match the bottom label on the label
stack. When it is clear, the present label value can
match to any label on the label stack
11: (for reserved labels)
The value field is encoded as:
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Label |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Type TBD2 - MPLS Match2
Function: MPLS Match2 applies to MPLS Label experiment bits
(EXP) on the top label in the label stack.
Encoding: <type (1 octet), [op, value]+>
[op,value] - Defines a list of {operation, value} pairs used
to match 3-bit exp field on the top label of packets
[RFC3032].
Values are encoded using a single byte, where the five most
significant bits are zero and the three least significant
bits contain the exp value.
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3. Deployment Example: DDoS Traffic
In this example, 5 local policy rules in the filter-based RIBs (FB-
RB, aka Policy Routing) will match n-tuples (destination IP address,
Destination Port, source IP address, Source IP Address, protocols
(ICMP and STCP). These policy rules can be created by standard yang
modules for filter-based RIBS (configuration, and ephemeral
configuration) or ACLs, or vendor based policy. These policies will
put the DDoS attack data onto one LSP (LSP1) in order to send the
DDoS traffic to the IDS/IPS processing attached to PE2.
The MPLS Filter allows the BGP Flow specification to match on the LSP
label rather than the IP address so that PE2 (with the FB-RIBs on
PE2) can forward the traffic to a set of IDS/IPS machines. The BGP
Flow Specification (BGP-FS) can forward this simple match policy
along with an action policy that constraints the traffic on this Flow
to a certain rate (bytes/second).
|<---------------- AS1 ----------------->|
+---------+ +-----+ +-----+ +-----+
===| PE1 |---|IBGP |----|IBGP |----| PE2 |--IDS-1/IPS
| Filters | | | | | | |--IDS-2/IPS
+---------+ +-----+ +-----+ +-----+
|-------------------------------|
MPLS travel on LSP-1 with label-1
BGP Flow Specification Filter 1
BGP Flow Specification
Match Policy
Destination IP address (0/0) [Required by RFC5575]
MPLS Label match (label-1)
Action Policy
Traffic-rate (n bytes)
4. Security Considerations
The validation of BGP Flow Specification policy is considered in
[I-D.hares-idr-flowspec-combo] for option 1, and for option 2. For
Option 1, the MPLS Match can be one of the match filtes, and and the
final match is an "AND" of all the filters. Match filters are tested
in the order specified in [I-D.hares-idr-flowspec-combo] and/or an
RFC5575bis document.
The traffic rate action described above is described in [RFC5575].
[I-D.hares-idr-flowspec-combo] suggests a default order for filters
and for the BGP-FS action proposed after [RFC5575], and this document
discusses how conflicts between action are handled.
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5. IANA Considerations
This section complies with [RFC7153]
IANA is requested to a new entry in "Flow Spec component types
registry" with the following values:
Value Name: Value Reference
=========== ===== =========
MPLS-Match1 TBD1 [This Document]
MPLS-Match2 TBD2 [This Document]
6. References
6.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<http://www.rfc-editor.org/info/rfc2119>.
[RFC3031] Rosen, E., Viswanathan, A., and R. Callon, "Multiprotocol
Label Switching Architecture", RFC 3031,
DOI 10.17487/RFC3031, January 2001,
<http://www.rfc-editor.org/info/rfc3031>.
[RFC3032] Rosen, E., Tappan, D., Fedorkow, G., Rekhter, Y.,
Farinacci, D., Li, T., and A. Conta, "MPLS Label Stack
Encoding", RFC 3032, DOI 10.17487/RFC3032, January 2001,
<http://www.rfc-editor.org/info/rfc3032>.
[RFC4271] Rekhter, Y., Ed., Li, T., Ed., and S. Hares, Ed., "A
Border Gateway Protocol 4 (BGP-4)", RFC 4271,
DOI 10.17487/RFC4271, January 2006,
<http://www.rfc-editor.org/info/rfc4271>.
[RFC5575] Marques, P., Sheth, N., Raszuk, R., Greene, B., Mauch, J.,
and D. McPherson, "Dissemination of Flow Specification
Rules", RFC 5575, DOI 10.17487/RFC5575, August 2009,
<http://www.rfc-editor.org/info/rfc5575>.
[RFC7153] Rosen, E. and Y. Rekhter, "IANA Registries for BGP
Extended Communities", RFC 7153, DOI 10.17487/RFC7153,
March 2014, <http://www.rfc-editor.org/info/rfc7153>.
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6.2. Informative References
[I-D.hares-idr-flowspec-combo]
Hares, S., "An Information Model for Basic Network Policy
and Filter Rules", draft-hares-idr-flowspec-combo-01 (work
in progress), March 2016.
[I-D.ietf-idr-bgp-flowspec-oid]
Uttaro, J., Filsfils, C., Smith, D., Alcaide, J., and P.
Mohapatra, "Revised Validation Procedure for BGP Flow
Specifications", draft-ietf-idr-bgp-flowspec-oid-03 (work
in progress), March 2016.
[I-D.ietf-idr-flow-spec-v6]
McPherson, D., Raszuk, R., Pithawala, B., Andy, A., and S.
Hares, "Dissemination of Flow Specification Rules for
IPv6", draft-ietf-idr-flow-spec-v6-07 (work in progress),
March 2016.
[I-D.ietf-idr-flowspec-l2vpn]
Weiguo, H., Litkowski, S., and S. Zhuang, "Dissemination
of Flow Specification Rules for L2 VPN", draft-ietf-idr-
flowspec-l2vpn-04 (work in progress), May 2016.
[I-D.liang-idr-bgp-flowspec-label]
Hares, S., You, J., Raszuk, R., and d. danma@cisco.com,
"Carrying Label Information for BGP FlowSpec", draft-
liang-idr-bgp-flowspec-label-02 (work in progress), March
2016.
Authors' Addresses
Lucy Yong
Huawei
Email: lucy.yong@huawei.com
Susan Hares
Huawei
7453 Hickory Hill
Saline, MI 48176
USA
Email: shares@ndzh.com
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Qiandeng Liang
Huawei
101 Software Avenue, Yuhuatai District
Nanjing 210012
China
Email: liangqiandeng@huawei.com
Jianjie You
Huawei
101 Software Avenue, Yuhuatai District
Nanjing 210012
China
Email: youjianjie@huawei.com
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